point source discharger sampling workshop for the drbc ... · workshop for the drbc stage 2 pcb...

Point Source Discharger SamplingWorkshop

for the DRBC Stage 2 PCB TMDL

PCB Analysis by EPA Method 1668A

January 11 & 20, 2005

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EPA Method 1668A

Method Background• EPA began method development in 1995• HRGC/HRMS used for selectivity and

sensitivity• Initially focused on the 12 CB congeners

designated as toxic by the World Health Organization (WHO) – the “WHO list” congeners

• Method was validated in 1995 by one lab– Pacific Analytical, Inc.

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Method Background• Method published in March 1997 (EPA-821-R-97-

001)• In mid-1997, EPA began expanding the method

for analysis of the 209 CB congeners (Method 1668A)

• Method validated by one lab (Axys Analytical Services)

• Method validation study published in March 2000• Study was peer reviewed and comments

incorporated into method revision• Method 1668A published in December 1999

– EPA-821-R-00-002

EPA Method 1668A

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Method Background• EPA initiated an Interlaboratory Method

Validation Study in the Fall of 2003• Includes analysis of wastewater, biosolids

and fish tissue• EPA reported delays in obtaining the

study data• Interlaboratory Method Validation Report

reportedly to be issued in early 2005

EPA Method 1668A

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Method Summary• Isotope dilution quantitation technique is used

for the 12 toxic WHO list congeners and the earliest and latest eluting congener at each level of chlorination (homolog group)

• 13C12- labeled analogs of the CBs. Added to the sample pre-extraction

• All other congeners are quantitated using the internal standard quantitation technique • Using a labeled compound that is not an

exact analog

EPA Method 1668A

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EPA Method 1668AMethod Summary (aqueous samples)• Extraction

• Aqueous – 1-L sample size extracted with methylene chloride using SPE, Separatory Funnel or CLLE

• Cleanups• Back-extraction with sulfuric acid and/or base, and GPC,

silica gel, or Florisil• Extract Concentration

• Solvent reduced to 20 ul• Analysis

• HRGC/HRMS with quantitation by isotope dilution or internal standard technique

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Project Analytical QC Requirements

Objective• Ensure that comparable data is generated

amongst the various stakeholders and laboratories to meet DRBC DQOs

Resources• DRBC website has summary of sampling and

analytical requirements• http://www.state.nj.us/drbc/PCB_info.htm• EPA Method 1668A Project QC Requirements

posted on the DRBC website

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Acrobat Document

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Project Analytical QC Requirements

• Analyze samples according to the project-specific modifications to EPA Method 1668A

• Questions or concerns with the QC requirements should be discussed with the DRBC prior to implementing any changes

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Project Analytical QC Requirements

Target Analyte List• Analyze samples for 209 congeners

Sample Collection, Storage and Holding Times• 2-L aqueous sample size

• COLLECT replicate volume in the event of breakage or reanalysis

• In some instances, collection of precisely a 2-liter volume may not be possible. If the sample size falls below 2-liters, the Estimated Detection Limits (EDLs) will become elevated above project objectives. If the volume exceeds 2-liters, the additional volume poses difficulties in extracting the sample properly. The sample size collected canacceptably range from 1.8-liters to 2.1-liters, but should be as close as possible to 2-liters.

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Project Analytical QC Requirements

Sample Collection, Storage and Holding Times• Lab must document container

cleanliness and traceability• 2-L amber glass container supplied by lab

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Project Analytical QC Requirements

Sample Collection, Storage and Holding Times• Lab must supply reagent grade water for field

blanksExtraction and Cleanup

• Entire contents of the sample volume must be extracted

• Do NOT separate solids if greater than 1% as described in Section 11.5 of Method 1668A

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Project Analytical QC Requirements

Extraction and Cleanup• All pre-extraction spike additions must be

added to the 2-L bottle containing the sample prior to extraction

• Lab may extract using equipment to accommodate the 2-L volume

• Alternatively – serially or simultaneously extract two 1-L portions.

• Combine solvent prior to cleanups• Concentrate samples to a final volume of

20 ul

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Project Analytical QC Requirements

Extraction and Cleanup• Process all method blanks, OPR samples,

field blanks or other QC samples IDENTICALLY to the samples including same extract cleanups

Column/Retention Time Calibration• Project requires the use of the SPB-octyl

column

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Project Analytical QC Requirements

Initial Calibration• Minimum of 5 levels for each of the

toxic/level of chlorination (LOC) congeners

• Low calibration standard for the project must be 0.5 ng/ml

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Project Analytical QC RequirementsMethod Blanks• Method blanks must meet the decision rules or

replicate sample(s) must be reextracted and reanalyzed• An individual congener cannot exceed 20 pg/L • If a congener exceeds 20 pg/L and the associated

sample concentration exceeds 10× the amount in the blank, then no action is required

• If a congener exceeds 20 pg/L and the congener is not found in the associated field sample, then no action is required

• The total PCB concentration cannot exceed 300 pg/L

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Project Analytical QC RequirementsRinsate Blanks• Rinsate blanks must meet the decision rules or

samples may need to be recollected and reanalyzed (decisions rules are an interim goal)• An individual congener cannot exceed 40 pg/L • If a congener exceeds 40 pg/L and the associated

sample concentration exceeds 3× the amount in the blank, then no action is required

• If a congener exceeds 40 pg/L and the congener is not found in the associated field sample, then no action is required

• The total PCB concentration cannot exceed 600 pg/L

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Project Analytical QC Requirements

Qualitative/Quantitative Issues• Data Reporting

• Report results for all 209 CB congeners• Report data using project Qualifier Codes

• Provides mechanism for reporting co-eluting congeners

• Report results according to hardcopy data package deliverable and DRBC EDD specification

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Acrobat Document Acrobat Document

Qualifier Codes Co-Eluting Congeners

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Project Analytical QC Requirements

• Data Reporting• Report data to the sample specific

Estimated Detection Limit (EDL)• “J” flag for values less than the

concentration equivalent to the low calibration standard but greater than the EDL

Acrobat Document

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Thank You

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